Imports System.Data.SqlClient
Dim conn As SqlConnection
Dim da As SqlDataAdapter
Dim ds As DataSet
Dim comm As SqlCommand
If TextBox1.Text = "wang" And TextBox2.Text = "123456789" Then
conn = New SqlConnection("Data Source=qc6\SQLEXPRESS;Initial Catalog=a1;Persist Security Info=True;User ID=" & TextBox1.Text & ";Password=" & TextBox2.Text)
sql()
Else
MsgBox("error")
End If
Sub sql()
Try
da = New SqlDataAdapter("select * from t1", conn)
ds = New DataSet()
da.Fill(ds, "ds")
DataGridView1.DataSource = ds.Tables("ds")
Catch ex As Exception
MsgBox("不对")
End Try
End Sub

不得了，我真的石的